Professor Andrew Mills from the University of Strathclyde is leading the research into the 'intelligent' plastic indicator

An intelligent food wrapping that changes colour if the contents are going bad has been created by scientists.

The smart plastic packaging detects when meat, fish or salad leaves have passed their use-by date or have been left out of the fridge for too long.

It also alerts householders if sealed packaging has been broken or damaged, putting the contents at risk.
The British scientists behind the intelligent wrap believe it will reduce unnecessary household waste and help cut the 8.3million tons of food being thrown away in the UK every year.

It will also help people uncertain about best-before and use-by dates on food – and reassure those who gamble with the dates on meat and dairy produce.

Previously, scientists have developed indicator labels which are inserted into food packaging. But the new plastic is designed to be part of the wrapping itself.

It works with food such as meat, fish or salad that has been sealed in a ‘modified atmosphere’ – where levels of oxygen are reduced and replaced with inert nitrogen or carbon dioxide gases to slow natural decay.

The new plastic is designed to change colour if levels of oxygen rise above a predetermined level.

Some packaged meat from a leading supermarket. Intelligent food wrapping that reacts to rising levels of oxygen and changes colour if the contents are going bad has been created

It also responds to chemical changes triggered by food spoiling.

Professor Andrew Mills, who is leading the research at Strathclyde University, said: ‘At the moment we throw out far too much food, which is environmentally and economically damaging. We hope this will reduce the risk of people eating food that is no longer fit for consumption and help prevent unnecessary waste of food.’

The project was part-funded by a £325,000 grant from Scottish Enterprise’s Proof of Concept programme, which aims to turn research ideas into commercial products.

The Government says 364,000 tons of edible food is thrown away each year after passing its best-before date, and another 39,400 tons is dumped without even being opened.

Prof Mills said the first smart wraps could be in the shops within two years.